Sometimes,the Rails (mostly written in Java, like RadRails, RubyMine, 3rd Rail, or Netbeans for Ruby) have some problems running with the default Ubuntu open source java interpretors. You may check the installed java version with:

For writing a short ToDo list, taking some notes from a conference or saving an interesting shell command, an Ubuntu user needs a simple sticky notes desktop widget. Tomboy Notes is the easyest to use but in the same time very well featured, and it is bundled in Gnome Desktop.